From Emily Calandrelli—Emmy-nominated host of Xploration Outer Space, correspondent on Bill Nye Saves the World, and graduate of MIT—comes the fourth novel in a fun illustrated chapter book series about an eight-year-old girl with a knack for science, math, and solving mysteries with technology.

Third grader and inventor extraordinaire Ada Lace has a new social studies teacher—who loves group projects. While most of the class has constructed regular dioramas with clay and construction paper, Ada, her best friend Nina, and sometimes nemesis Milton have built a complex scale model of an historic silver mine. But when Milton reveals that he added his “old Milton touch” on their project right before turning it in, Ada worries that he has sabotaged their work.

In a desperate attempt to save their project, Ada and Nina use their combined creative and technical prowess to perform a heist and break into their teacher’s supply closet after school.

Do the two friends have what it takes to deceive the school’s security system? Or will they get caught trying to pull off this seemingly impossible mission.

Ada Lace. It concerns me to see you in detention,” said Ms. Lily. “I know you love science, and your curiosity is admirable. But it has its limits. You can’t just help yourself to school equipment after hours. Am I making myself clear?”

“Yes, Ms. Lily,” said Ada.

“The rules are for everyone to follow. You don’t get special treatment because your dad’s a teacher here.”

“I know, Ms. Lily. I didn’t mean . . .” Ms. Lily held up her hand, and Ada closed her mouth. She’d always gotten along well with her principal. It didn’t feel good to be in trouble with her.

“I know you know. But it doesn’t hurt for you to hear it from me. Now, let’s make sure we don’t meet like this again, okay?”

“Okay, Ms. Lily.”

• • •

Milton was waiting outside. They had been on opposite sides of the room in the same detention.

“How come you didn’t have to talk to her?” Ada asked.

“Aw, they’re used to seeing me here. Stick with me, kid. They’ll get used to you, too.”

“No, thanks,” said Ada. Ada and Milton hadn’t been doing anything bad. Not really. They had just found a weird bug after school, and they used the science lab to dissect it. Ada had permission to be in the art room after school, with her dad, or outside, but all the other classrooms were off-limits.

“I never thought Ms. Azalea would turn us in. She’s usually so nice!” said Ada.

“Yeah, but the risk is half the fun, right?” said Milton.

“Speak for yourself,” said Ada. They got to the west entrance, near Mr. Lace’s room. Milton was supposed to meet his mom outside.

“Wanna hang out later?” Milton asked.

“Nah, I have homework,” said Ada, “and I’m not allowed to hang out today anyway.”

“Tomorrow?”

“If Nina can come too.”

“I guess,” said Milton. Ada kept hoping that Milton and Nina would start to like each other more. It hadn’t happened yet.

• • •

The worst part about trying to hang out with Nina and Milton at the same time was that they could never agree on anything. But Ada was determined to make it work. Usually that meant waiting until Nina and Milton both got tired of arguing, and suggesting something that they could agree on. Unfortunately, neither of them was that excited about the compromise. Ada suggested a movie instead of a water balloon toss (Milton) or creating a Juniper Garden swap shop (Nina). They agreed, and Ada was relieved. Then she realized they also had to agree on which movie to go see.

“But you’ve seen that Wizards of Weird movie,” said Milton.

“I know! But it’s totally rewatchable,” said Nina.

“How do you know?” said Ada.

“I’ve seen it twice!” said Nina.

“Okay. Why don’t we start with stuff we haven’t seen?” Ada suggested.

That left Teeny Tiny Kitten Frenzy, which was too cute even for Nina, and Mission Probable. Usually Ada didn’t like heist movies, but she decided to give it a try. Ada’s mom brought them to the theater, and while Ada, Nina, and Milton watched their movie, Ms. Lace, Elliott, and Jack went to see Teeny Tiny Kittens.

“You guys are making such a big mistake,” said Elliott. “Do you know how many kittens there are???”

Ada was surprised at how much she enjoyed Mission Probable. It was pretty easy to figure out what was going to happen next. In fact, Nina kept leaning over to whisper to Ada what was coming up. But there was technology Ada hadn’t ever seen in a movie before. It was all kind of rough and homemade looking, which made it seem like a lot of it could be created at home. And some of the ways the thieves navigated the security were different from what she had seen in other movies. For example, instead of slinking around the security laser beams like ninjas, they used mirrors to divert the security beams around them. Nothing looked like it was something from the future. Instead, all their tools looked like something Mr. Peebles might be able to put together. It totally captured Ada’s imagination.

• • •

“That was so cool, wasn’t it?” said Milton.

“A little on the predictable side, don’tcha think?” said Nina.

“Oh, like seeing W of W for a third time?” said Milton. Nina rolled her eyes.

“Well, I thought all the tools were cool,” said Ada.

“Yes! Exactly!” said Milton. “It makes heists look fun.”

“Too bad they’re so illegal,” said Nina.

“Yeah,” said Ada. “It is kind of too bad.”

• • •

They met Elliott, Jack, and Ms. Lace outside the bathrooms.

“How was it, Ell?” Ada asked.

“A little disappointing,” said Elliott. Ada was surprised.

“Why?”

“Well, first of all, there were only four hundred and ninety cats. I’m pretty sure they used some of the cats over again,” said Elliott.

“And they weren’t nearly as fuzzy as I was expecting,” said Jack.

“So, thumbs down?” said Nina.

“Just wait for it to stream,” said Elliott.

• • •

Later that night in bed, as Ada drifted off to sleep, she imagined she was scaling an unbelievably tall building using gecko gloves. She got to the top floor and looked in the window to see Milton. He smiled and waved. Then he opened the window, which tilted outward, and Ada was sent plunging down to the street below. She woke with a gasp. The noise woke George, who instantly played a lullaby. Ada drifted off to sleep again.

• • •

The next day in class, the students were assigned a social studies project. They were studying industries in the Bay Area, and the teacher had them work in pairs.

Their usual teacher, Ms. Grunflecker, was out on family leave and had been replaced by a substitute, Mr. Parable. He was okay, but he tried way too hard. It was amusing the first day when Mr. Parable wore a tie shaped like a slice of pizza. And then maybe the second day when he wore a fish tie. Then, on the third day, he moved on to a baseball bat tie. And after that they just kept rotating: pizza slice, fish, bat, pizza slice, fish, bat—always in that order. It took all the whimsy out of it.

He also had a parrot named Ferris Bueller in the classroom. That was fun at first too, but it got annoying really quickly. Every time Mr. Parable asked a question, the parrot would shout, “I know! I know!” And Mr. Parable would say, “Bueller,” then the bird would say, “I don’t know.” It was clear that Mr. Parable and Bueller had only ever taught for a week at a time. They ran out of material by the second week.

Even worse, if you left your desk to sharpen your pencil, the bird would say, “Have a seat! Have a seat!” And Mr. Parable would always take the bird’s side!

Nina was much more tolerant of the sub, but even she started to complain when Mr. Parable assigned partners and she got Milton.

“I was that guy’s biggest champion,” said Nina, “and he sticks me with Milton? Doesn’t he know who his friends are?”

“Oh, come on! Milton’s not so bad,” said Ada.

“You’re just saying that because you guys are buddies now.”

“Yeah, but doesn’t that count?”

“I guess. . . .”

• • •

At dinner Ada complained to her mom about the parrot.

“His name’s Ferris Bueller?” said Ms. Lace, laughing.

“Yeah. Why is that funny?”

“Oh, it’s just from this great movie from the . . .”

“The nineties?” said Ada. She was usually interested in her parents’ lives before she was born, but she was sick of Bueller.

“From the eighties, actually, Ada,” said Mr. Lace. “And it wasn’t that great a movie.”

“Oh, come on! It’s a classic!” said Ms. Lace.

“Citizen Kane is a classic,” said Mr. Lace.

“Well, the parrot is annoying,” said Ada.

“I have to agree with you there,” said Mr. Lace.

• • •

That night, just as Ada was falling asleep, Milton called her on the ham. Ada’s parents had rules about this: no calls after 8:30 p.m. She tried to ignore him, but Milton was persistent.

KD8PKR. KD8PKR. This is KD86E. Over.

KD8PKR! Psssstttt! Ada? It’s Milton.

Milton. What do you want? I’m trying to . . .

I have some great ideas for a heist!

Okay, well, good luck to you. I’m not a thief, and I’m not supposed to be . . .

Of course, it was then that Mr. Lace came in.

“Ada? What did we say about the radio? Good night, Milton,” he said into the mic and clicked it off.

“I was trying to tell him, but . . .”

“You shouldn’t even have the radio on after bedtime,” said Mr. Lace.

“I forgot! I’m sorry.”

“Next time, you’re going to lose it for a week.”

“It wasn’t my fault!”

“Good night, Adita.” He gave her a kiss on the forehead. “You know, I’m glad that you and Milton are getting along better, but you may want to set some limits for him.”

“Yeah, I know,” said Ada. “I can already feel the trouble starting to rub off on me.”

“Well, we can’t have that,” Mr. Lace said as he closed Ada’s door.

• • •

The next day during social studies, Ada’s partner was missing. Mr. Parable told Ada that Pixie had strep throat and might not be in for the rest of the week.

“How about you work with Milton and Tina?”

“Nina!” both Ada and Nina said at the same time.

Ada was more annoyed by this name confusion than Nina was. Probably because Nina was relieved not to be working alone with Milton. Ada was concerned though. If she was trying to spend less time with Milton, this was not going to help.

Emily Calandrelli is an executive producer and the host of Xploration Outer Space, where she shows viewers the most exciting projects in the space industry today and a correspondent on the new series, Bill Nye Saves the World. Emily has a technical background with mechanical and aerospace engineering degrees from West Virginia University and Master’s degrees in aeronautics and astronautics as well as technology and policy from MIT. Emily is a professional speaker and writer and is passionate about exciting students and their families about science and space exploration. Emily is also deeply passionate about getting more girls interested in STEM and STEM careers. She lives in San Francisco. Learn more at TheSpaceGal.com.